Sensibly equivalent¶ to:
The EF54 is a VHF high-slope pentode and has a sharp cut-off, the 5A/156M is the Type designation for the valve made by STC.
The cathode is brought out to several pins to provide a low inductance path, part way to a ring connection as found in co-axial valves. A feature of the design is aligned grids that provide conditions to reduce partition noise.
The 5A/156M was capable of operation up to 200 MHz.
The reverse is a plain aluminium screening can over the all-glass valve inside.
The wide glass tube envelope is 33 mm in diameter and, excluding the B9G base pins, is 60 mm tall.
References: Data-sheet & 1043. Type 5A/156M was first introduced in 1947.
Absolute Maximum Operating Conditions¶
Updated June 18, 2020. shape:wide.glass.tube construction:all.glass type:pentode age:1940.1950 base:b9g heater:6.3v pins:9 pin:1.h pin:2.a pin:3.g2 pin:4.k pin:5.k pin:6.g1 pin:7.k pin:8.k pin:9.h